Various air distribution systems and air-flow diverters have been proposed for use in heating, ventilating, and air conditioning (HVAC) systems. For example, U.S. Pat. No. 4,413,550 in the name of Piano and issued on Nov. 8, 1983 discloses a ventilating system that is intended to maximize the vehicle passenger's sensations of comfort with respect to air flow and temperature. It achieves this by supplying the passenger compartment with two series of air flows. The first is a series of substantially pulsating air flows, each of which is cyclically discontinued for a predetermined period of time and directed to the upper passenger compartment at the head zone. The second is a substantially continuous air flow directed into the lower passenger compartment at the lower torso and foot zone. The method of ventilation is realized by a rotatable member, which is similar to a cam. The rotatable member is located inside of a cylindrical housing and is operated by a geared motor unit. The air is controlled by rotating disks that are also rotated by the motor unit.
Another patent disclosing an air distribution system can be seen in U.S. Pat. No. 4,216,822 in the name of Izumi and issued on Aug. 12, 1980. This patent shows an airflow distributing device for an automotive air conditioning system. The device serves to mix a selected ratio of hot and cold air to achieve a desired temperature and then distributes the air at desired ratios between selected passenger areas. For this purpose, the device uses a rotatably fixed mode plate and a cylindrical chamber subdivided into three cells with each of the cells respectively communicating with a selected portion of the passenger compartment. In this manner, the device is able to control the ratio of hot and cold air into any of the three cells in whole or in controlled separate amounts.
In addition, the U.S. Pat. No. 3,661,069 in the name of Grosseau and issued on May 9, 1972 shows an air distribution device that has similarities to the device seen in the above mentioned '822 patent. In this instance, Grosseau uses a multi-damper door set-up that serves to mix a selected ratio of hot and cold air to achieve a desired temperature and then distributes the air at desired ratios between selected passenger areas. Grosseau utilizes a main cylindrical housing subdivided into two compartments by a rotatable blade-type shutter to control the direction of the climatized air into one or both of the air outlets available. The climatized air is obtained by the use of two additional shutters for the control of fresh and warm air stream ratios.